Best Pool Chemical Calculator Apps (2026): 12 Apps Worth Downloading

Pooli is the most complete pool app in this list. You dip a test strip, hold it against the Color Correct card, and the app reads the pads, then turns the reading into a dose in the right order, with the reason for each step. It also tracks what the chemicals cost you each month, by pool, and follows the weather so a storm or heatwave changes the advice.

The price is the catch to read carefully. The free tier covers up to 2 pools with manual testing, while Club Plus costs $13 a month or $99 a year and adds scanning, weather follow-ups and deeper reports. Test strips are not included in Plus, so you buy them separately; Club Max ships them. Choose Pooli when you want one app to scan, dose and track costs.

Pool Math is the calculator behind the Trouble Free Pool method, and it shows in the depth: calculators for pH, free chlorine, calcium hardness, salt, total alkalinity, borates and the Calcium Saturation Index, plus logs for maintenance, chemical additions, filter pressure and salt-water-generator settings. It tells you exactly how much of each chemical to add for your pool's real volume.

The free download is nearly a demo — it keeps only a one-day log, and full history needs Premium at $7.99 a year. That is still the cheapest paid price in this list, and there is no monthly option. Pick Pool Math when you follow the Trouble Free Pool method and want CSI dosing; pick Pooli or AquaCheck when you want the app to read the strip for you.

The Orenda Calculator is the thinking owner's free app. Instead of checking each chemical against a simple range, it balances water by the Langelier Saturation Index, which measures whether water will scale surfaces or corrode equipment. That is the same method pool professionals use, and the app adds a pool volume estimator and how-to videos so a careful owner can learn it.

It is free, with no subscription and no paywall on the calculator, and it is built by Orenda Technologies, now owned by HASA, a major pool chemical maker. The trade-off is the learning curve: LSI balancing is more technical than range checks, and the app leans toward Orenda's proactive chemistry approach. Choose it when you want professional-grade balancing for free.

Pool Care by Swim University is the most hand-holding app here. You test your water with whatever kit you own, enter the numbers, and get a custom treatment plan in under a minute: exact chemicals, exact amounts, in the right order, with waiting times between additions. Inside the app, on-demand education and live chat with real pool professionals cover problems from algae to filter cleaning.

The price is plain: $49.99 a year after a 7-day free trial, with no monthly option and no free version, since the company states that free apps usually mean the user is the product. The honest limits are that it handles one pool only, and that it assumes you already test your water. Buy it when you want guidance, not just math.

AquaCheck solves the two problems most pool apps leave open: order and volume. Its wizard enforces the sequence of total alkalinity, then pH, then hardness, then chlorine, then stabilizer, with timers between steps, and it calculates one exact total for your actual pool volume instead of a generic rate per 10,000 liters. The free tier runs in your browser with no account and no install.

The catch is that exact doses are a Pro feature, at £2.99 a month or £19.99 a year with 7 days free on the annual plan, while the free tier gives the report, the order and the timers. It is priced in pounds, so a US owner pays the converted amount. Pick AquaCheck when the order of treatment matters most to you.

The Clorox Pool App is the free app for do-it-yourself owners who already buy Clorox Pool&Spa products. Its scan-to-test technology reads a photo of your test strip and gives expert water analysis, product recommendations and exact doses, and you can add the products straight to a Walmart, Amazon or Lowe's cart while standing at the pool. A personalized Pool Plan and reminders keep the routine on track.

The limit is the brand lock-in: the water analysis recommendations are designed for use with the Clorox Pool&Spa products named in the analysis, so owners who buy other brands get doses for chemicals they do not own. History also stops at your last 10 analyses. Choose it when Clorox is already your chemical brand.

Test to Swim is HTH's free water-testing app, and it is free in the full sense: the app is free to download with no subscription required to scan strips, get recommendations or save test history. One photo of an HTH 6-Way strip reads free chlorine, bromine, pH, total alkalinity, calcium hardness and cyanuric acid, and a free myHTH account saves every test so you can watch trends week to week.

The catch is the strip lock-in. Scanning works with HTH 6-Way strips, so owners who test with another brand must type readings in by hand or use a different app. It is also built for US owners only. Pick Test to Swim when HTH strips are already in your shed.

Pool Calculator is the simplest app in this list, and that is the point. It does the math for chlorine, pH, total alkalinity, calcium hardness, cyanuric acid, salt and bromine, tells you exactly how much of each chemical to add, and adds a volume calculator and a what-if calculator that shows what happens to the water when you add a chemical. It works offline, so poor reception by the pool does not matter.

It is completely free, with no in-app purchases or subscriptions, and it works with whichever test strip or kit you prefer. The trade-offs are real: there is no test history saving, no strip scanning and no reminders. Choose it when you want a free calculator and nothing else.

Clean Pool keeps its pricing to one line: try everything free for 30 days, then $10 a year, with no feature gates, no tiers and no surprises. One subscription covers every device, hosting and updates are included, and there is a 30-day money-back guarantee. At $10 a year it costs less than one bag of shock, which is the point the maker makes on its own pricing page.

The trade-off is track record. Clean Pool is a newer, smaller app than Pooli or Pool Math, and it has no test-strip scanning, so readings go in by hand. There is also no monthly option — the year is charged at once. Pick Clean Pool when you want the cheapest full app and you are happy typing readings in.

Skimmer is the iPhone-first answer to pool chemistry: log pH, free chlorine, alkalinity, calcium hardness, cyanuric acid and salt, and the app shows balanced, drifting or out-of-range status at a glance. It also logs every chemical dose and service, and exports a clean PDF of the pool's history for the day you sell the house.

Skimmer Pro costs $19.99 a year after a 7-day free trial, and the maker pitches it plainly against Pool Math's $7.99 a year: a newer app that costs more but looks and feels like a modern iPhone app. The limits are platform and input — iPhone only, and readings are typed in by hand. Choose it when you live on an iPhone.

Pool Pilot takes the opposite approach to the brand apps: manual testing is free forever, and the strip scanner reads any brand — AquaChek, HTH, Taylor, Clorox or Pentair — the same way every time. Dosing comes from your pool's real volume, your product's strength and the Calcium Saturation Index, and safety timers tell you when it is safe to swim after treatment.

The part to check before you commit is the scanning price. The app's own listing says manual testing is free forever, while strip scanning is a paid subscription, and the price is shown only inside the app, not on a public pricing page. Pick Pool Pilot when you refuse to be locked into one strip brand.

AquaChek Connect is the free companion to AquaChek's Select Connect strips. The app uses photo capture to scan the strip and gives a personalized water treatment recommendation, with no registration required and no account to create. It also carries a built-in water volume calculator and an in-app test history, and links to AquaChek so you can find a shop that stocks the strips.

The catch is the same as every brand scanner: it only works with the app-enabled strips in the Select Connect Starter Kit, and refills are a recurring purchase. There is no LSI balancing and no trend analysis beyond the history. Choose it when AquaChek strips are already what you buy.